While Armenian constitutes the sole member of the Armenian branch of the Indo-European family, Aram Kossian has suggested that the hypothetical Mushki language may have been a (now extinct) Armenic language.[39].

W. M. Austin (1942) concluded[40] that there was an early contact between Armenian and Anatolian languages, based on what he considered common archaisms, such as the lack of a feminine gender and the absence of inherited long vowels. However, unlike shared innovations (or synapomorphies), the common retention of archaisms (or symplesiomorphy) is not considered conclusive evidence of a period of common isolated development. There are words used in Armenian that are generally believed to have been borrowed from Anatolian languages, particularly from Luwian, although some researchers have identified possible Hittite loanwords as well.[41]

In 1985, Soviet linguist Igor M. Diakonoff noted the presence in Classical Armenian of what he calls a "Caucasian substratum" identified by earlier scholars, consisting of loans from the Kartvelian and Northeast Caucasian languages.[42] Noting that Hurro-Urartian-speaking peoples inhabited the Armenian homeland in the second millennium BC, Diakonoff identifies in Armenian a Hurro-Urartian substratum of social, cultural, and animal and plant terms such as ałaxin "slave girl" ( ← Hurr. al(l)a(e)ḫḫenne), cov "sea" ( ← Urart. ṣûǝ "(inland) sea"), ułt "camel" ( ← Hurr. uḷtu), and xnjor "apple(tree)" ( ← Hurr. ḫinzuri). Some of the terms he gives admittedly have an Akkadian or Sumerian provenance, but he suggests they were borrowed through Hurrian or Urartian. Given that these borrowings do not undergo sound changes characteristic of the development of Armenian from Proto-Indo-European, he dates their borrowing to a time before the written record but after the Proto-Armenian language stage.

Loan words from Iranian languages, along with the other ancient accounts such as that of Xenophon above, initially led linguists to erroneously classify Armenian as an Iranian language. Scholars such as Paul de Lagarde and F. Müller believed that the similarities between the two languages meant that Armenian belonged to the Iranian language family.[43] The distinctness of Armenian was recognized when philologist Heinrich Hübschmann (1875)[43][44] used the comparative method to distinguish two layers of Iranian words from the older Armenian vocabulary. He showed that Armenian often had 2 morphemes for the one concept, and the non-Iranian components yielded a consistent PIE pattern distinct from Iranian, and also demonstrated that the inflectional morphology was different from that in Iranian languages.

The hypothesis that Greek is Armenian's closest living relative originates with Holger Pedersen (1924), who noted that the number of Greek-Armenian lexical cognates is greater than that of agreements between Armenian and any other Indo-European language. Antoine Meillet (1925, 1927) further investigated morphological and phonological agreement, postulating that the parent languages of Greek and Armenian were dialects in immediate geographical proximity in the Proto-Indo-European period. Meillet's hypothesis became popular in the wake of his book Esquisse d'une histoire de la langue latine (1936). Georg Renatus Solta (1960) does not go as far as postulating a Proto-Graeco-Armenian stage, but he concludes that considering both the lexicon and morphology, Greek is clearly the dialect most closely related to Armenian. Eric P. Hamp (1976, 91) supports the Graeco-Armenian thesis, anticipating even a time "when we should speak of Helleno-Armenian" (meaning the postulate of a Graeco-Armenian proto-language). Armenian shares the augment, and a negator derived from the set phrase Proto-Indo-European language*ne h₂oyu kʷid ("never anything" or "always nothing"), and the representation of word-initial laryngeals by prothetic vowels, and other phonological and morphological peculiarities with Greek. Nevertheless, as Fortson (2004) comments, "by the time we reach our earliest Armenian records in the 5th century AD, the evidence of any such early kinship has been reduced to a few tantalizing pieces".

Many modern scholars have rejected the Graeco-Armenian hypothesis, arguing that the linguistic proximity between the two languages has been overstated.[32][45][46][47][48]

Used in tandem with the Graeco-Armenian hypothesis, the Armenian language would also be included under the label Aryano-Greco-Armenic, splitting into proto-Greek/Phrygian and "Armeno-Aryan" (ancestor of Armenian and Indo-Iranian).[27][28]

Classical Armenian (Arm: grabar), attested from the 5th century to the 19th century as the literary standard (up to the 11th century also as a spoken language with different varieties), was partially superseded by Middle Armenian, attested from the 12th century to the 18th century. Specialized literature prefers "Old Armenian" for grabar as a whole, and designates as "Classical" the language used in the 5th century literature, "Post-Classical" from the late 5th to 8th centuries, and "Late Grabar" that of the period covering the 8th to 11th centuries. Later, it was used mainly in religious and specialized literature, with the exception of a revival during the early modern period, when attempts were made to establish it as the language of a literary renaissance, with neoclassical inclinations, through the creation and dissemination of literature in varied genres, especially by the Mekhitarists. The first Armenian periodical, Azdarar, was published in grabar in 1794.

The Book of Lamentations by Gregory of Narek (951–1003) is an example of the development of a literature and writing style of Old Armenian by the 10th century. In addition to elevating the literary style and vocabulary of the Armenian language by adding well above a thousand new words,[59] through his other hymns and poems Gregory paved the way for his successors to include secular themes and vernacular language in their writings. The thematic shift from mainly religious texts to writings with secular outlooks further enhanced and enriched the vocabulary. “A Word of Wisdom”, a poem by Hovhannes Sargavak devoted to a starling, legitimizes poetry devoted to nature, love, or female beauty. Gradually, the interests of the population at large were reflected in other literary works as well. Konsdantin Yerzinkatsi and several others even take the unusual step of criticizing the ecclesiastic establishment and addressing the social issues of the Armenian homeland. However, these changes represented the nature of the literary style and syntax, but they did not constitute immense changes to the fundamentals of the grammar or the morphology of the language. Often, when writers codify a spoken dialect, other language users are then encouraged to imitate that structure through the literary device known as parallelism.[60]

The Four Gospels, 1495, Portrait of St Mark Wellcome with Armenian inscriptions

First printed Armenian language Bible, 1666

In the 19th century, the traditional Armenian homeland was once again divided. This time Eastern Armenia was conquered from Qajar Iran by the Russian Empire, while Western Armenia, containing two thirds of historical Armenia, remained under Ottoman control. The antagonistic relationship between the Russian and Ottoman empires led to creation of two separate and different environments under which Armenians lived. Halfway through the 19th century, two important concentrations of Armenian communities were further consolidated.[61] Because of persecutions or the search for better economic opportunities, many Armenians living under Ottoman rule gradually moved to Istanbul, whereas Tbilisi became the center of Armenians living under Russian rule. These two cosmopolitan cities very soon became the primary poles of Armenian intellectual and cultural life.[62]

The introduction of new literary forms and styles, as well as many new ideas sweeping Europe, reached Armenians living in both regions. This created an ever-growing need to elevate the vernacular, Ashkharhabar, to the dignity of a modern literary language, in contrast to the now-anachronistic Grabar. Numerous dialects existed in the traditional Armenian regions, which, different as they were, had certain morphological and phonetic features in common. On the basis of these features two major standards emerged:

Western standard: The influx of immigrants from different parts of the traditional Armenian homeland to Istanbul crystallized the common elements of the regional dialects, paving the way for a style of writing that required a shorter and more flexible learning curve than Grabar.

Eastern standard: The Yerevan dialect provided the primary elements of Eastern Armenian, centered in Tbilisi, Georgia. Similar to the Western Armenian variant, the Modern Eastern was in many ways more practical and accessible to the masses than Grabar.

Both centers vigorously pursued the promotion of Ashkharhabar. The proliferation of newspapers in both versions (Eastern & Western) and the development of a network of schools where modern Armenian was taught, dramatically increased the rate of literacy (in spite of the obstacles by the colonial administrators), even in remote rural areas. The emergence of literary works entirely written in the modern versions increasingly legitimized the language's existence. By the turn of the 20th century both varieties of the one modern Armenian language prevailed over Grabar and opened the path to a new and simplified grammatical structure of the language in the two different cultural spheres. Apart from several morphological, phonetic, and grammatical differences, the largely common vocabulary and generally analogous rules of grammatical fundamentals allows users of one variant to understand the other as long as they are fluent in one of the literary standards.[63]

After World War I, the existence of the two modern versions of the same language was sanctioned even more clearly. The Armenian Soviet Socialist Republic (1920–1990) used Eastern Armenian as its official language, whereas the diaspora created after the Armenian Genocide preserved the Western Armenian dialect.

Armenian language road sign.

The two modern literary dialects, Western (originally associated with writers in the Ottoman Empire) and Eastern (originally associated with writers in the Russian Empire), removed almost all of their Turkish lexical influences in the 20th century, primarily following the Armenian Genocide.[64]

In Armenian, the stress falls on the last syllable unless the last syllable contains the definite article [ə] or [n], and the possessive articles ս and դ, in which case it falls on the penultimate one. For instance, [ɑχɔɾˈʒɑk], [mɑʁɑdɑˈnɔs], [ɡiˈni] but [vɑˈhɑɡən] and [ˈdɑʃtə]. Exceptions to this rule are some words with the final letter է (ե in the reformed orthography) (մի՛թէ, մի՛գուցե, ո՛րեւէ) and sometimes the ordinal numerals (վե՛ցերորդ, տա՛սներորդ, etc.), as well as նաեւ, նամանաւանդ, հիմա, այժմ, and a small number of other words.

Modern Armenian has six monophthongs. Each vowel phoneme in the table is represented by three symbols. The first indicates the phoneme's pronunciation in the International Phonetic Alphabet (IPA). After that appears the corresponding letter of the Armenian alphabet. The last symbol is its Latin transliteration (according to ISO 9985).

The major phonetic difference between dialects is in the reflexes of Classical Armenian voice-onset time. The seven dialect types have the following correspondences, illustrated with the t–d series:[68]

Armenian corresponds with other Indo-European languages in its structure, but it shares distinctive sounds and features of its grammar with neighboring languages of the Caucasus region. Armenian is rich in combinations of consonants.[69][70] Both classical Armenian and the modern spoken and literary dialects have a complicated system of noun declension, with six or seven noun cases but no gender. In modern Armenian, the use of auxiliary verbs to show tense (comparable to will in "he will go") has generally supplemented the inflected verbs of Classical Armenian. Negative verbs are conjugated differently from positive ones (as in English "he goes" and "he does not go") in many tenses, otherwise adding only the negative չ to the positive conjugation. Grammatically, early forms of Armenian had much in common with classical Greek and Latin, but the modern language, like modern Greek, has undergone many transformations, adding some analytic features.

Classical Armenian has no grammatical gender, not even in the pronoun, but there is a feminine suffix (-ուհի "-uhi"). For example, ուսուցիչ (usuts'ich, "teacher") becomes ուսուցչուհի (usuts'chuhi, female teacher). This suffix, however, does not have a grammatical effect on the sentence. The nominal inflection, however, preserves several types of inherited stem classes. Nouns are declined for one of seven cases: nominative (ուղղական uxxakan), accusative (հայցական hayc'akan), locative (ներգոյական nergoyakan), genitive (սեռական seṙakan), dative (տրական trakan), ablative (բացառական bac'aṙakan), or instrumental (գործիական gorciakan).

For example, Eastern Armenian speakers pronounce (թ) as [tʰ], (դ) as [d], and (տ) as a tenuis occlusive [t˭]. Western Armenian has simplified the occlusive system into a simple division between voiced occlusives and aspirated ones; the first series corresponds to the tenuis series of Eastern Armenian, and the second corresponds to the Eastern voiced and aspirated series. Thus, the Western dialect pronounces both (թ) and (դ) as [tʰ], and the (տ) letter as [d].

There is no precise linguistic border between one dialect and another because there is nearly always a dialect transition zone of some size between pairs of geographically identified dialects.

Armenian can be divided into two major dialectal blocks and those blocks into individual dialects, though many of the Western Armenian dialects have become extinct due to the effects of the Armenian Genocide. In addition, neither dialect is completely homogeneous: any dialect can be subdivided into several subdialects. Although Western and Eastern Armenian are often described as different dialects of the same language, many subdialects are not readily mutually intelligible. Nevertheless, a fluent speaker of one of two greatly varying dialects who is also literate in one of the standards, when exposed to the other dialect for a period of time will be able to understand the other with relative ease.

Western Armenian dialects are currently spoken also in Gavar (formerly Nor Bayazet and Kamo, on the west of Lake Sevan), Aparan, and Talin in Armenia (Mush dialect), and by the large Armenian population residing in Abkhazia, where they are considered to be the first or second ethnic minority, or even equal in number to the local Abkhaz population[74]

The Armenian alphabet (Armenian: Հայոց գրեր, romanized: Hayots grer or Armenian: Հայոց այբուբեն, romanized: Hayots aybuben) is a graphically unique alphabetical writing system that is used to write the Armenian language. It was introduced around AD 405 by Mesrop Mashtots, an Armenian linguist and ecclesiastical leader, and originally contained 36 letters. Two more letters, օ (o) and ֆ (f), were added in the Middle Ages.

During the 1920s orthography reform in Soviet Armenia, a new letter և (capital ԵՎ) was added, which was a ligature before ե+ւ, whereas the letter Ւ ւ was discarded and reintroduced as part of a new letter ՈՒ ու (which was a digraph before). This alphabet and associated orthography is used by most Armenian speakers of the Republic of Armenia and the countries of the former Soviet Union. Neither the alphabet nor the orthography has been adopted by Diaspora Armenians, including Eastern Armenian speakers of Iran and all Western Armenian speakers, who keep using the traditional alphabet and spelling.

^Armenian has no legal status in Samtske-Javakheti, but it is widely spoken by its Armenian population, which is concentrated in Ninotsminda and Akhalkalaki districts (over 90% of the total population in these two districts).[11] There were 144 state-funded schools in the region as of 2010 where Armenian is the main language of instruction.[12][13]

^The Lebanese government recognizes Armenian as a minority language,[14] particularly for educational purposes.[15][16]

^Hadjilyra, Alexander - Michael. "The Armenians of Cyprus"(PDF). publications.gov.cy. Press and Information Office, Republic of Cyprus. p. 15. Archived from the original(PDF) on 14 December 2019. According to the European Charter for Regional or Minority Languages of the Council of Europe, Armenian was recognised as a minority language of Cyprus as of 1 December 2002.

^"Iraqi Constitution: Article 4"(PDF). The Republic of Iraq Ministry of Interior General Directorate for Nationality. Archived from the original(PDF) on 28 November 2016. Retrieved 16 June 2014. The right of Iraqis to educate their children in their mother tongue, such as Turkmen, Syriac, and Armenian shall be guaranteed in government educational institutions in accordance with educational guidelines, or in any other language in private educational institutions.

^Pisarek, Walery (2009). "The relationship between official and minority languages in Poland"(PDF). efnil.org. European Federation of National Institutions for Language. p. 118. Archived from the original(PDF) on 14 December 2019. In a Statement made by the Republic of Poland with relation to the ratification of the European Charter for Regional or Minority Languages, Belarusian, Czech, Hebrew, Yiddish, Karaim, Kashubian, Lithuanian, Lemkian, German, Armenian, Romani, Russian, Slovak, Tatar and Ukrainian were recognized as minority languages.

^Saib, Jilali (2001). "Languages in Turkey". In Extra, Guus; Gorter, Durk (eds.). The Other Languages of Europe: Demographic, Sociolinguistic and Educational Perspectives. Philadelphia: Multilingual Matters. p. 423. ISBN9781853595097. No other language can be taught as a mother language other than Armenian, Greek and Hebrew, as agreed in the Lausanne Treaty ...

^Okçabol, Rıfat (2008). "Secondary Education in Turkey". In Nohl, Arnd-Michael; Akkoyunlu-Wigley, Arzu; Wigley, Simon (eds.). Education in Turkey. Berlin: Waxmann Verlag. p. 65. ISBN9783830970699. Private Minority Schools are the school established by Greek, Armenian and Hebrew minorities during the era of the Ottoman Empire and covered by Lausanne Treaty.

^"H. Acharian Institute of Language". sci.am. Archived from the original on 5 October 2014. Main Fields of Activity: investigation of the structure and functioning, history and comparative grammar of the Armenian language, exploration of the literary Eastern and Western Armenian Language, dialectology, regulation of literary language, development of terminology

^Baliozian, Ara (1975). The Armenians: Their History and Culture. Kar Publishing House. p. 65. There are two main dialects: Eastern Armenian (Soviet Armenia, Persia), and Western Armenian (Middle East, Europe, and America) . They are mutually intelligible.

^Campbell, George (2003). "Armenian, Modern Standard". Concise Compendium of the World's Languages. Routledge. p. 33. ISBN9781134720279. This second form is known as Western Armenian; Eastern Armenian is the written and spoken language used in the CIS. The two forms are mutually intelligible, indeed very close to each other.

^A. Bammesberger in The Cambridge History of the English Language, 1992, ISBN978-0-521-26474-7, p. 32: the model "still remains the background of much creative work in Indo-European reconstruction" even though it is "by no means uniformly accepted by all scholars".